Bags made of thermoplastic materials are in widespread use in grocery and retail businesses, substantially replacing the use of paper bags. These thermoplastic bags, commonly referred to as "plastic bags" or "t-shirt bags", enjoy several advantages over paper bags, such as their light weight, strength and water resistance. Plastic bags are also compact when laid flat, which allows numerous bags to be stacked one atop another to form bag packs, for ease of handling and shipping.
Systems have been developed to dispense individual bags from a bag pack and to facilitate the handling and loading of the individual bag upon separation from the bag pack. Generally speaking, these systems employs a rack for mounting or propping up a bag pack and for supporting an individual plastic bag separated from the pack, to allow a user to load goods into the separated plastic bag without having to hold it up.
One such system is shown in U.S. Pat. No. Re 33,264 (Baxley et al.), a reissue of U.S. Pat. No. 4,676,378, and assigned to Sonoco Products Company. The rack has two spaced rods for supporting the stacked handles of a back pack, and has a hook element between the two rods for receiving a central detachable mounting tab on the bag pack. The handles of the bags in the bag pack have rod receiving apertures formed by partially severed flaps. The flaps are heat bonded together throughout the full stack to maintain aperture alignment. The patent teaches that rods can sever the aligning flaps when the bag pack is placed onto the rods. If the flaps are not fully severed and only folded down by the rods, then the handles tend to sever from the flaps as individual bags are removed from the bag pack. Likewise, the central mounting tab is severed from each bag as it is removed from the pack. When a bag pack is used up, a clump of mounting tabs is left on the hook element and must be discarded, as well as two clumps of flaps. This creates substantial needless waste, and requires someone to take extra time to remove and dispose of the clump of tabs from the central hook before loading another bag pack onto the rack.
To facilitate the opening and dispensing of consecutive bags in the Baxley system, the rear panel of each bag may be provided with a dab of readily disengageable adhesive. The adhesive bonds the rear panel of a first bag with the front panel of an adjacent second bag. The bond on the rear panel is supposed to draw the front panel of the second bag forwardly as the first bag is removed from the rack, thus severing the front panel from the central mounting tab. The forward movement of the severed front panel of the second bag is stopped by upturned ends on the support arms of the rack. The upturned ends provide a resistive force which is greater than the adhesive's bonding force, thus allowing the bond to be severed as the first bag is removed, leaving the second bag in a fully open loading position.
Another very similar system is shown in U.S. Pat. No. 5,020,750 (Vrooman et al.), also assigned to Sonoco Products Company. This patent makes specific reference to U.S. Pat. No. 4,676,378, noting that successful use of the prior art system requires a user to first practice with it. Certain problems with the manual opening of consecutive bags are also mentioned, specifically where a user breaks both the front and back wall of each consecutive bag from the central mounting tab, proper positioning of the bag in an open loading position on the rack is harder.
To try to overcome these problems, Vrooman teaches that when a loaded first bag is being removed from the rack, the adhesive bond on its rear wall will first pull the front wall of an adjacent second bag outwardly, severing the front wall from the detachable mounting tab because the strength of the adhesive bond is greater than the detachable mounting tab's severance strength. As the first bag continues to move off of the rack, its rear wall pulls the front wall of the next bag forwardly, causing the apertures in the handles of the second bag to slide forwardly on the arms of the rack. The arms include portions of greater resistive force. The rear wall of the first bag then disengages from the front wall of the second bag because the resistive force against sliding along the arms is greater than the adhesive's bond strength.
The Vrooman system suffers from the same disadvantage as the Baxley system, namely a clump of mounting tabs must be collected, removed and discarded when a bag pack is used up.
Another disadvantage of both prior systems is the use of the adhesive between bags. Cashiers and other frequent users of these systems get the adhesive all over their fingers, which is a health risk since it might be ingested, or cause eye problems if rubbed in the eye or the like. This system is also not hygienic since dirt is attracted and adheres to the fingers. The sticky dirty fingers also interfere with the cashier's operation of the cash register, and interferes with the bagging operation as well because the bag material sticks to the fingers.
Yet another drawback of the Vrooman system is the difficulty in removing a loaded bag off of the rack's arms. The holes in the bag's handles do not slide easily over the rubber end portions at the ends of the support arms. The enlarged balls at the ends of the support arms also interfere with removal of the handles. A user must shimmy and repeatedly jerk the handles over the end portions to free the handles from the arms. This is a particularly uncomfortable and, over the course of a few hours, a physically tiring operation for cashiers. Since the racks are often arranged sideways to a cashier (i.e. the rack's arms are oriented parallel to the long axis of the checkout counter), the cashier must perform the shimmying with one arm outstretched to reach the bag handle on the far arm of the rack.
What is desired therefore is a bag dispensing system having a bag pack insertable on a rack which allows a user to automatically and easily set a bag in a position ready for loading after another loaded bag is removed off of the rack. The loading position should be achieved without employing any extra adhesive between the individual bags of a back pack. The rack should not unduly interfere with the removal of a loaded bag off the rack. Further, once all of the bags in a bag pack have been dispensed, there should be no plastic material left over which must be collected and disposed of as trash.